Bicuspid tooth and backing.



F. 2. HANSCOM. BICUSPID TOOTH AND BACKING. APPLICATION FILED NOV. 30. 1911.

Patented N 0v. 5, 1918.

citizen of-the United- States, and a resident Frank 2. nnnscom, or

.BICUSPID roo'rr:

Toall whom/it m ayconcem: 1

Be it knownthat If, FRANK Z: HAnscoM, a

of'Elm-hurst," Dupage county, State of Illinoisg have invented certainnew and useful Improvements in Bicusp'id- Teeth and Back ings, of which the following, taken in connec'ztionwithhe drawings, is a description.

-' arranged that; a greater My invention has forits object the produ'ction-ofartificial teeth, more particularly" those-known as bieuspid teeth, 4 with backings' therefor,- which are so constructed and portion of'the porcelain material maybe used in-ma'king-the tooth and requiring less material in'fthe backing'ftherefor, which isnsually 'ofi gold or--othe r; preci ous'metals, thereby greatly redueingthe 'cost of mak ngthe samef It has longfbeen customary to use porce lain as the material out; of which artificial teeth are made,='without due regard to'certainf properties inherent in porcelain which prohibit its successful usein any way Where there is a possibility-of its becoming curved or warped during'thesoldering or otherwise securing it to the backing, and also that y poroelain isieasi'ly'fractured at any point where there is an opening or scored and weakened line formed therein. For-this reason I have soFconstru'cted my teeth withthe largest possible body portion of porcelain at a point where a *hole is to be: drilled for the purpose ofengagingit-he oasing,:thereby givingeach i shape the" tooth that theffront thereof will 1 as :nearly as: possible resemble the natural tooth: greater vstrength and rigidity than has been customary in former Constructions.

A furthe'r ob'jectrof :my invention is to so tooth, while'the rear or posterior portion thereofis formedon straight :or beveled lines tofit the. metal casing or backing provided for theitooth. 3 o

, -A 'fl1l'hh61'l0bj86b of. my invention is. to provide. an artificial tooth ofthis kind so shaped and bonstructedwith respect to the-backing or casing forming part of the-bridge work, I that the 1 porcelain part ofthe tooth fits very zcloselyz into the casing. providedtherefor, 'so

that when the parts are assembled there are no [hollow ispaces pr caivitlesk between the tooth and :thexbackmg;

Specification of Letters Patent.

1 Application filed November30, 1917. Serial No-.-204,738.

1 structedi ELMHUBST, ILLINOIS.

AND BACKING.

Batented Nov. 5,--l91 8.1

In :the "accompanying: drawing, I have illustrated what I now consider the best ema bodlment of my invention as applied'to a biuspidtooth, and in these drawings,

Figure 1 1s a vertical sectional v ew ithrbllgh fitooth and casing therefor;

F1g.=12 is a fragmentary front elevati of V a bridge comprising the-invention;

Fig. 3 is a front elevation of a1 bicuspidtooth with-the casing therefor;

Fig; 4c isa side elevation thereof; Fig. 5 is a rear elevation; Fig; 6 is bottom .plan: view, and

Fig. 7 is an interior view of the casing 01'. backing. of thetooth; 7 7

Referring to; thedraw ng, the body portlon of'the tooth Azis constructed and shaped as nearly as possible like the natural tooth,

which in thls instance is thebicuspid tooth,

and for' the purpose-of description willbe 7 considered as an upper tooth. r

The front or 1 bial surface of the tooth a is curved or convex, as shown more'particw larlv in Figs: 1 and 4. The inner or cervical surface-of thetoothis preferably concave,

as shown at a, extendingfrom the extreme upper edge of the tooth to the edge of the back area-or lingual surface. a When to be used this concave surfacea will be ground and fitted to the gums of the wearer. i In making theseteeth, I contemplate making them in standard sizes to fit thebackings, or casings be observedin :the I drawings, I' have conhe body portionof the toothwith the largest possible area ofporcelain at the point of a greatest strength,- and have iar .i ranged all the fitting edges of the toothconn ing in contact with the casing with plain or beveled surfaces, so that there will be no therefor, the dentist having only to fit the inner -or cervical surfacesthereof to the gums of thewearer. As-will' 1 chance ofi'fracture or cleavage in assembling the nor willthere be any hollow space between the'tbody of the tooth and the backin or bridgework. i 7 {he lower orocclusal surface of the upper tooth here shown is divided by line a extending from the center of the labial sur face a, rearwardly:

100 Y to-the lingnal Surface, a X presentinghon-each side ofieald centralline a bevel-angle, a a of irregular area, as shown more particularly in Figs. 4: and 5.

The sides also of said tooth, a a present bevel-angles on lines extending from the occlusal surface to the edge of the labial surface at the front of the tooth to the concave cervical surface, a, and the lingual surface, a at the rear of the body portlon of the tooth, A. As will be observed more particularly in Figs. 1 and 4, the lingual surface a is flat and presents a beveled surface inclining downwardly from the edge of the cervical surface.

A socket b is provided in the body portion of said tooth, which extends inwardly from the lingual surface, a either in a horizontal direction, or, if desired, it may be extended at an angle upwardly or downwardly from the horizontal line. This socket, b, is adapted to receive a pin projecting from the. casing, which will be hereinafter explained.

The bevel-angle a a at the sides of each tooth provide an area between the contiguous teeth for the upwardly extending wings in the casings which inclose the occlusal surface of the tooth.

The backings or casings B for these teeth are preferably formed of metal, and are made by drop forging or casting the same. These casings are also made in standard sizes, so that the dentist may easily and quickly assemble the same with the porce lain portions which are made to fit them.

The casings are provided with up wardly extending wings, b, b, on each side thereof. The interior of the casing is divided at the center with a line 0, corresponding to the line (/9, in the porcelain portion of the tooth and has the bevel-angle surfaces, 0, 0, corresponding to the bevelangle surfaces a a, of each tooth. The bevelangles, (1, (1,, are inclosed by the corresponding angles, c 0 in the casing.

The cusp, C, of the tooth is formed as nearly possible like the natural tooth and extends from the center of the labial surface across the entire occlusal. surface and incloses the lingual surface of the porcelain portion of the tooth. Projecting inwardly from the lingual surface of the casing G is a pin or projection, 0 which engages the socket b of the porcelain portion.

When these teeth are to be used, the dentist assembles the porcelain portion into this casing, soldering and cementing the same together in the usual manner. The wings, I), of the casing inclosing the sides of the teeth, firmly and securely hold the same together, forming a strong and durable construction able to stand. any strain placed upon the teeth in both horizontal and vertical directions. The teeth are inserted and cemented in place in the usual. manner.

By this form of construction, it will be observed that I have provided a tooth having a body portion of porcelain, which is much cheaper material than metal, and have constructed a tooth having the properties of durability required, as well as conforming more easily to the appearance of the natural tooth than those as heretofore constructed, and with. all the necessary supports and braces required to maintain the tooth in position, giving it the necessary wearing surface for mastication as needed for bicuspid teeth. Forming the body portion of the tooth of porcelain, as I have, with the bevel-angles fitting standard casings provided with requisite retaining means, the tooth is not at any time subject to any strains having a tendency to warp the structure, causing breakage of the material.

I claim: a

1. An artificial tooth having a body portion of greater thickness from the labial t0 the lingual surface than from the labial to the cervical surface, the occlusal surface of said tooth having oppositely facing bevelangles upon each side of a rearwardly extending central line, substantially as described.

2. An artificial tooth having a body portion of greater thickness from the labial to the lingual surface than from the labial to the cervical. surface, the occlusal surface of said tooth having oppositely facing bevelangles upon each side of a rearwardly extending central line, and a bevel-angle upon each side of said tooth extending from the first named angle to the cervical surface thereof, substantially as described.

3. An artificial tooth comprising a body portion of greater thickness from the labial to the lingual surface than from the labial to the cervical surface, oppositely facing bevel-angles upon the occlusal surface and upon the sides of said tooth, a beveled lingual surface on the body portion of the tooth said body portion having a socket therein entering through the lingual surface, substantially as described.

4:. An artificial tooth having a body portion of greater thickness from the labial to the lingual surface thereof than from the labial to the cervical surface, bevel-angles on the occlusal surface and the sides of said tooth, the body portion of said tooth provided with a socket entering from the lingual surface, and a casing having the inte rior thereof provided with bevel-angle surfaces closely fitting the bevel-angles of the tooth, substantially as described.

An artificial tooth having a body portion of greater thickness from the labial to the lingual surface than from the labial to the cervical surface, oppositely facing bevel-angles on the occlusal surface and. the

sides of said tooth, the lingual surface of provided in the body portion of the tooth said tooth providing a bevel-angle, and a substantially as described. 1 casing having the interior thereof provided In testimony whereof I have signed this with bevel-angle surfaces closely fitting the specification.

5 bevel-angles of the tooth, and said casing provided with a pin projecting into a socket FRANK Z. HANSCOM Copies of this patent may be obtained for five cents each, by addressing the Commissioner of latentl. Washington, D. 0. 

